package com.sxf.spring.security;

import java.util.Collection;
import java.util.Iterator;
import java.util.List;

import org.springframework.security.access.AccessDecisionVoter;
import org.springframework.security.access.AccessDeniedException;
import org.springframework.security.access.ConfigAttribute;
import org.springframework.security.access.vote.AbstractAccessDecisionManager;
import org.springframework.security.authentication.InsufficientAuthenticationException;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.GrantedAuthority;

public class CustomAccessDecisionManager extends AbstractAccessDecisionManager {

	protected CustomAccessDecisionManager(
			List<AccessDecisionVoter<? extends Object>> decisionVoters) {
		super(decisionVoters);
	}

	/**
	 * 裁定当前用户对应权限authentication是否包含所请求资源所拥有的权限<br>
	 * 如果成立 则通过裁定 否则发生异常
	 */
	public void decide(Authentication authentication, Object object,
			Collection<ConfigAttribute> configAttributes)
			throws AccessDeniedException, InsufficientAuthenticationException {
		if (configAttributes == null) {
			return;
		}
		// 所请求的资源拥有的权限(一个资源对多个权限)
		Iterator<ConfigAttribute> iterator = configAttributes.iterator();
		while (iterator.hasNext()) {
			ConfigAttribute configAttribute = iterator.next();
			// 访问所请求资源所需要的权限
			String needPermission = configAttribute.getAttribute();
			System.out.println("needPermission is " + needPermission);
			// 用户所拥有的权限authentication
			for (GrantedAuthority ga : authentication.getAuthorities()) {
				if (needPermission.equals(ga.getAuthority())) {
					return;
				}
			}
		}
		// 没有权限
		throw new AccessDeniedException(" No Access Dendied ");
	}

}